Job Hazard Analysis: Irrigation installation

A general example for this task. Your JHA should reflect your crew, equipment and site — review it with a competent person before work starts.

Steps, hazards and controls

1. 1. Confirm utility locates and lay out zones, heads, and trench lines.

   • Hitting a buried gas, electric, water, or communication line later during digging.High
     • Do not dig until the 811 ticket is clear and all utilities are marked. Check the ticket number and date.
     • Ask the owner about private lines: lighting, propane, septic, wells, old sprinkler lines. Flag them.
     • Route trench lines away from marks. Where you must cross, plan to hand-dig.
   • Heat and sun exposure during layout.Medium
     • Set up shade and cool water before starting. Drink a cup every 15–20 minutes.
     • Wear a wide-brim hat or hard hat with sun shade and light long sleeves.

2. 2. Unload the trencher and dig trenches; hand-dig at utility crossings.

   • Entanglement or amputation from the trencher digging chain.High
     • Only trained operators run the trencher. Check guards and the operator-presence control before use.
     • Keep everyone at least 10 ft from the boom. Never step over the boom or chain.
     • Shut off the engine and wait for the chain to stop before clearing rocks or roots.
     • No loose clothing, hoodie strings, or dangling jewelry near the machine.
   • Striking a buried utility line.High
     • Hand-dig with a shovel inside the tolerance zone around each mark. Expose the line before crossing it with the trencher.
     • If you hit or find an unmarked line, stop all digging and call the supervisor.
   • Trencher tipping or rolling off the trailer ramps during unloading.Medium
     • Park the trailer on level ground, chock the wheels, and lock the ramps in place.
     • Use a spotter. Nobody stands downhill or beside the ramps.
   • Loud engine noise and flying dirt or rocks.Medium
     • Wear earplugs or earmuffs and safety glasses while the trencher runs.
     • Wet very dry soil lightly to cut dust.

3. 3. Lay pipe in the trench and pull poly or drip line.

   • Tripping into open trenches or twisting an ankle on spoil piles.Medium
     • Keep spoil on one side, at least 2 ft back from the trench edge.
     • Mark open trenches with flags or caution tape, and backfill sections as soon as they pass inspection.
   • Back strain from carrying pipe bundles and poly rolls.Medium
     • Use a wheelbarrow or utility cart. Carry 20-ft pipe sticks with two people.
     • Lift with your legs and keep the load close. Don't twist.

4. 4. Cut and glue PVC fittings with primer and cement.

   • Flammable primer and cement vapors catching fire.Medium
     • No smoking or open flame within 25 ft of open cans. Keep cans closed when not in use.
     • Store cans in the truck out of direct sun. Keep a fire extinguisher on the truck.
   • Breathing solvent fumes and skin or eye contact with primer and cement.Medium
     • Read the SDS. Glue in open air, stand upwind, and don't put your face over the trench while gluing.
     • Wear nitrile gloves and safety glasses. Wash hands before eating or drinking.
   • Cuts and pinched fingers from ratchet pipe cutters and utility knives.Low
     • Keep fingers clear of the cutter jaws. Deburr pipe ends with a deburring tool, not a knife pulled toward you.
     • Wear cut-resistant work gloves when cutting.

5. 5. Tie into the water supply and install the backflow device and valve manifolds.

   • Pressurized water spraying out when the line is cut.Medium
     • Shut off the main valve and open a faucet to drain pressure before cutting in.
     • Tell the owner before shutting off water. Tag the closed main so nobody reopens it.
   • Burns or fire if sweating copper fittings with a torch.Medium
     • Use push-fit or compression fittings when allowed, so no torch is needed.
     • If you must solder, clear dry grass and mulch, use a heat shield, keep a fire extinguisher within reach, and watch the area 30 minutes after.

6. 6. Run valve wire and mount the controller.

   • Electric shock from 120V power at the controller.High
     • Use a plug-in controller on an existing GFCI outlet when possible.
     • If the controller is hardwired, a qualified electrician does it with the breaker off, locked, and tagged.
     • Keep the transformer plugged out while you connect low-voltage valve wires.
   • Drilling through a wall into hidden wires or pipes when mounting the controller.Medium
     • Check the wall with a stud and wire finder before drilling. Drill only as deep as needed.
     • Inspect the cord and use a GFCI on outdoor power tools.

7. 7. Flush and pressure-test the system, then backfill and compact trenches.

   • Fittings or caps blowing off under pressure and hitting the face or eyes.Medium
     • Let PVC cement cure for the time on the can before pressurizing.
     • Open the valve slowly. Stand to the side of risers and caps, not over them.
   • Hand and arm vibration, noise, and foot injuries from the plate compactor.Medium
     • Rotate operators every 30 minutes. Keep feet clear of the plate.
     • Wear hearing protection and steel-toe or composite-toe boots.
   • Strain from shoveling backfill in the heat.Medium
     • Use the trencher backfill blade or a skid steer for long runs instead of shoveling.
     • Take shade breaks. Watch each other for dizziness, cramps, or confusion.

8. 8. Clean up, load equipment, and secure the site.

   • Trips over pipe scraps, tools, and open valve boxes.Low
     • Pick up scraps and empty cans as you go. Put lids on every valve box before leaving.
   • Trencher or compactor falling while loading onto the trailer.Medium
     • Use locked ramps and a spotter. Strap down equipment with rated straps or chains.